16 AA Rechargeable Batteries for $25(expired)
16-pack of Panasonic Eneloop AA 2000mAh Rechargeable NiMH Batteries for $25 today ($1.57 each).
They normally sell a 8-pack for $19 ($2.38 each).
The Eneloop batteries are some of the best quality rechargeable batteries.
If you are near an IKEA store, they sell a 4-pack AA for $7 or 4-pack AAA for $7 ($1.75 each), which are the same as the Panasonic Eneloop batteries.